Hybrid vigour and combining ability in long duration pigeonpea [Cajanus cajan (L.) Millsp.] hybrids involving male sterile lines

Abstract

Hybrids, utilizing three genetic male sterile lines (DAMS-1, ICPMS 3783 and KPMS 1050) and 12 diverse genotypes of the long duration group of pigeonpea [Cajanus cajan (L.) Millspj were evaluated for general and specific combining ability, variance components and standard heterosis. Among the lines DA 32, DA 34, DA 37, DA 46, DA 93-4, DA 93-2, DA 94-6 and Bahar mutant and testers DAMS-1 and ICPMS 3783 were found to be good general combiners for seed yield/plant-1 and other yield contributing traits such as secondary branches/plant-1, clusters/planC1 and number of pods/planc1. The tester DAMS-1 was also a good general combiner for primary brancheslplanc1 and per cent pod setting. The estimates of a2gca and a2sca suggested partial dominance of additive genetic action for number of pods/planc1. While for days to flowering, days to maturity, plant height, number of primary branches/planc1, per cent pod setting, harvest index and seed yield/planc1 over dominance with non additive genetic variance was observed. The contribution of testers to the performance of crosses were found significant for seed yield/planC1 and yield attributing traits. Out of 36 cross combinations 10 showed higher magnitude of specific combining ability effects involving high x high (H x H) and low x high (L x H) combining ability effects of lines and testers, respectively for seed yield/plant-1, number of secondary branches/planc1 clusters/planc!, number of pods plant and per cent pod setting. The estimated standard heterosis ranged from 144.32 per .cent (KPMS 1050 x DA 94-6) to 8.75 per cent (MS 3783 x DA 37). Out of 36 combinations, 12 registered highly significant positive heterosis for seed yieldlplanc1 and number of primary and secondary branches/planc1 clusters plant and number of pods/planc1.